We have completed a Phase I study of extracorporeal membrane oxygenation (ECMO) in newborn respiratory failure. ECMO was used only in moribund infants (90%+ mortality risk) as determined by the neonatologists and measured by the newborn pulmonary insufficiency index (NPII). Thirty one of 55 infants (56%) survived. The incidence of intracranial bleeding, bronchopulmonary dysplasia, and the expense appears less in the ECMO treated infant. We are currently engaged in a controlled-randomized (Phase II) study of ECMO in newborn respiratory failure. By the end of the current grant year we expect to complete this study in infants over 2 kg birth weight. The results to date indicate that ECMO will be better than conventional ventilator management. We now propose to complete the Phase II study in infants 1-2 kg birth weight, and carry out a Phase III study comparing cost and morbidity in ECMO treated patients to those treated with conventional therapy.